Refactor http/client to return response body instead of full response

This means we don't have to use clone() to access the body, which closes #85

src/http/client.ts

@@ -1,10 +1,11 @@
 import { createLogger } from '../logger'
 
-const logger = createLogger('http')
+type BodyPromise = Promise<string>
 
+const logger = createLogger('http')
 let requestTimeout = 0
 let lastTimestamp = 0
-const promiseCache = new Map<string, Promise<Response>>()
+const promiseCache = new Map<string, BodyPromise>()
 
 const createRequestParams = (): RequestInit => {
   return {
@@ -20,7 +21,11 @@ export const setRequestTimeout = (timeoutMs: number) => {
   logger.info(`Using ${timeoutMs} millisecond timeout for HTTP requests`)
 }
 
-export const getDedupedResponse = async (timestamp: number, url: string): Promise<Response> => {
+const resolveBody = async (request: Request): BodyPromise => {
+  return (await fetch(request)).text()
+}
+
+export const getDedupedResponseBody = async (timestamp: number, url: string): BodyPromise => {
   // Clear the cache whenever the timestamp changes
   if (timestamp !== lastTimestamp) {
     lastTimestamp = timestamp
@@ -35,7 +40,7 @@ export const getDedupedResponse = async (timestamp: number, url: string): Promis
 
   const request = new Request(url, createRequestParams())
   logger.debug(`GET ${url}`)
-  const promise = fetch(request)
+  const promise = resolveBody(request)
   promiseCache.set(key, promise)
 
   return promise

src/sensor/iotawatt.ts

@@ -9,7 +9,7 @@ import {
   PowerSensorPollFunction,
 } from '../sensor'
 import { Circuit } from '../circuit'
-import { getDedupedResponse } from '../http/client'
+import { getDedupedResponseBody } from '../http/client'
 import { Characteristics } from '../characteristics'
 import { createLogger } from '../logger'
 
@@ -114,10 +114,10 @@ export const getSensorData: PowerSensorPollFunction = async (
   const sensor = circuit.sensor as IotawattSensor
 
   try {
-    const configurationResult = (await getDedupedResponse(timestamp, getConfigurationUrl(sensor))).clone()
-    const configuration = (await configurationResult.json()) as IotawattConfiguration
-    const statusResult = (await getDedupedResponse(timestamp, getStatusUrl(sensor))).clone()
-    const status = (await statusResult.json()) as IotawattStatus
+    const configurationResult = await getDedupedResponseBody(timestamp, getConfigurationUrl(sensor))
+    const configuration = JSON.parse(configurationResult) as unknown as IotawattConfiguration
+    const statusResult = await getDedupedResponseBody(timestamp, getStatusUrl(sensor))
+    const status = JSON.parse(statusResult) as unknown as IotawattStatus
 
     return {
       timestamp: timestamp,
@@ -142,8 +142,8 @@ export const getCharacteristicsSensorData: CharacteristicsSensorPollFunction = a
   const sensor = characteristics.sensor as IotawattCharacteristicsSensor
 
   try {
-    const queryResult = (await getDedupedResponse(timestamp, getQueryUrl(sensor))).clone()
-    const query = (await queryResult.json()) as IotawattCharacteristicsQuery
+    const queryResult = await getDedupedResponseBody(timestamp, getQueryUrl(sensor))
+    const query = JSON.parse(queryResult) as unknown as IotawattCharacteristicsQuery
 
     return {
       timestamp: timestamp,

src/sensor/shelly.ts

@@ -10,7 +10,7 @@ import {
   ShellyType,
 } from '../sensor'
 import { Circuit } from '../circuit'
-import { getDedupedResponse } from '../http/client'
+import { getDedupedResponseBody } from '../http/client'
 import { Characteristics } from '../characteristics'
 import { createLogger } from '../logger'
 
@@ -64,10 +64,10 @@ const getSensorDataUrl = (sensor: ShellySensor | ShellyCharacteristicsSensor): s
 const parseGen1Response = async (
   timestamp: number,
   circuit: Circuit,
-  httpResponse: Response,
+  responseBody: string,
 ): Promise<PowerSensorData> => {
   const sensor = circuit.sensor as ShellySensor
-  const data = (await httpResponse.json()) as Gen1StatusResult
+  const data = JSON.parse(responseBody) as unknown as Gen1StatusResult
 
   return {
     timestamp: timestamp,
@@ -79,9 +79,9 @@ const parseGen1Response = async (
 const parseGen2PMResponse = async (
   timestamp: number,
   circuit: Circuit,
-  httpResponse: Response,
+  responseBody: string,
 ): Promise<PowerSensorData> => {
-  const data = (await httpResponse.json()) as Gen2SwitchGetStatusResult
+  const data = JSON.parse(responseBody) as unknown as Gen2SwitchGetStatusResult
 
   return {
     timestamp: timestamp,
@@ -93,10 +93,10 @@ const parseGen2PMResponse = async (
 const parseGen2EMResponse = async (
   timestamp: number,
   circuit: Circuit,
-  httpResponse: Response,
+  responseBody: string,
 ): Promise<PowerSensorData> => {
   const sensor = circuit.sensor as ShellySensor
-  const data = (await httpResponse.json()) as Gen2EMGetStatusResult
+  const data = JSON.parse(responseBody) as unknown as Gen2EMGetStatusResult
 
   let power = 0
   let apparentPower = 0
@@ -136,16 +136,16 @@ export const getSensorData: PowerSensorPollFunction = async (
   const url = getSensorDataUrl(sensor)
 
   try {
-    const httpResponse = (await getDedupedResponse(timestamp, url)).clone()
+    const responseBody = await getDedupedResponseBody(timestamp, url)
 
     // Parse the response differently depending on what type of Shelly we're dealing with
     switch (sensor.shelly.type as ShellyType) {
       case ShellyType.Gen1:
-        return await parseGen1Response(timestamp, circuit, httpResponse)
+        return await parseGen1Response(timestamp, circuit, responseBody)
       case ShellyType.Gen2PM:
-        return await parseGen2PMResponse(timestamp, circuit, httpResponse)
+        return await parseGen2PMResponse(timestamp, circuit, responseBody)
       case ShellyType.Gen2EM:
-        return await parseGen2EMResponse(timestamp, circuit, httpResponse)
+        return await parseGen2EMResponse(timestamp, circuit, responseBody)
     }
   } catch (e) {
     logger.error(e)
@@ -166,8 +166,8 @@ export const getCharacteristicsSensorData: CharacteristicsSensorPollFunction = a
   }
 
   try {
-    const httpResponse = (await getDedupedResponse(timestamp, url)).clone()
-    const data = (await httpResponse.json()) as Gen2EMGetStatusResult
+    const result = await getDedupedResponseBody(timestamp, url)
+    const data = JSON.parse(result) as unknown as Gen2EMGetStatusResult
 
     let voltage = 0
     let frequency = 0

tests/sensor/shelly.test.ts

@@ -10,8 +10,8 @@ const gen2pmResponse = fs.readFileSync('./tests/sensor/shelly-plus-1pm.Switch.Ge
 
 // Mock getDedupedResponse calls to return real-world data
 jest.mock('../../src/http/client', () => ({
-  getDedupedResponse: async (timestamp: number, url: string) => {
-    let contents: string | null = null
+  getDedupedResponseBody: async (timestamp: number, url: string): Promise<string> => {
+    let contents = ''
 
     switch (url) {
       case 'http://127.0.0.1/status':
@@ -25,7 +25,7 @@ jest.mock('../../src/http/client', () => ({
         break
     }
 
-    return Promise.resolve(new Response(contents))
+    return Promise.resolve(contents)
   },
 }))